منابع مشابه
Carbon , nitrogen , oxygen and lithium abundances of six cool supergiants in the SMC ?
Carbon, nitrogen and oxygen abundances were derived from high-resolution spectra of 6 cool supergiants of the Small Magellanic Cloud. Oxygen-to-iron ratios (mean value [O/Fe] ≈–0.18 dex) are found to be similar to those found in young objects in the LMC and the Galaxy. This result is discussed in terms of chemical evolution. A mean deficiency of the carbon-to-iron ratio of [C/Fe] ≈–0.3 dex and ...
متن کاملPulsations in hot supergiants
Massive stars are the cosmic engines that shape and drive our Universe. Many issues such as their formation, their stability and the mass loss effects, are far from being completely understood. Recent ground-based and space observations have shown pulsations in massive MS and post-MS stars, such as acoustic and gravity modes excited by the κ-mechanism and even solar-like oscillations. Theoretic...
متن کاملChemical composition of six K supergiants in the Small Magellanic Cloud
A sample of six SMC cool stars (K supergiants) are analysed by high resolution spectroscopy in order to investigate their chemical content, which should reflect that of the current interstellar medium within the SMC. The abundance of Na, Al, α-elements, Fe peak and heavy elements are derived through an LTE analysis of the lines, compared to a Galactic ”standard” (the well-studied K giant Arctur...
متن کاملRadii and Effective Temperatures for K and M Giants and Supergiants. Ii
We present new interferometric observations for 74 luminous red stars, made in the near-infrared. We show that our 2.2 km uniform-disk diameters agree with other near-infrared diameter determinations (lunar occultations and interferometers) for 22 stars measured in common with ours. From our new data, we derive e†ective temperatures that are compared with our previous work and with comparable o...
متن کاملRadii and Effective Temperatures for G, K, and M Giants and Supergiants
Interferometrically determined angular diameters obtained at the Palomar Testbed Interferometer (PTI) for 69 giant and supergiant stars are presented. Spectral types of the 59 giant stars generally lie between G6 and M6, although a B7 giant is included ; the nine bright giants and supergiants have spectral types between F5 and M5. Comparison of the results to those from the IR Optical Telescope...
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ژورنال
عنوان ژورنال: Monthly Notices of the Royal Astronomical Society
سال: 1973
ISSN: 0035-8711,1365-2966
DOI: 10.1093/mnras/163.3.337